Pentium M vs. Pentium 4

Hi,
I just purchased an IBM Thinkpad R40 laptop off of ebay, and have been reading that to find the comparable Pentium 4 you would multiply the clock speed by 2x. (PM 1.4Ghz = P4 2.8Ghz) Is this true? I am also wondering if this laptop is an improvement over my current one, a Gateway M305CRV with a Celeron 2.4Ghz. Both systems will have 1gb of RAM. Thanks in advance for your help.

 

That a 1.4GHz Pentium M offers similar performance to a 2.8GHz Pentium 4 is a fairly good approximation, but if it's like an early Pentium M compared to a late Pentium 4, that approximation could be off a considerable amount. Either way it also says nothing about the fact that the P4 probably uses twice as much power.

The Celeron in the Gateway looks to be a P4 derivative, so it's probably a little slower than both.

 

Hi,
The Pentium M and Pentium 4 laptops were used ones on ebay, so a few years old. So it looks like this one will be an upgrade. Thanks for the quick reply.

 

I wouldn't say 2x, but probably at least 50% faster than P4s. Pentium Ms were the capability-per-clock kings of their day. The original Core Duos used Pentium M derived cores.

 

Yeah, they are not 2x as powerful for a given clockspeed. That approximation is almost correct for core 2 processors vs pentium 4's and pentium D's though.

 

So you're saying my 1.4Ghz Pentium M will be comparable to a 2.1Ghz Pentium 4? Would that still be better than my Celeron mentioned above?

 

Depends what you're going to be using the computer for. If there is a specific application, you can probably benchmark it.

 

Let me give you the SuperPI 1M results on my old desktop and laptop:

Desktop:
Pentium 4 2.4GHz, 533MHz FSB, 512K L2 cache: 1m 14secs

Laptop:
Pentium M 2.13GHz, 533MHz FSB, 2M L2 cache: 36.5 secs

Now you do the math...


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As usual you can find almost every CPU benchmarked here: PassMark Software - CPU Benchmarks - List of Benchmarked CPUs

 

Thanks for the link. It looks like the Pentium M is ahead of the Celeron by 30.

Pentium M: 307
Celeron: 277

 

I know a Dothan 1.5Ghz --> ~2.4Ghz Pentium 4. so I'd say a 1.4 (assuming Dothan) --> 2.2Ghz P4.